The honor code is carved into stone at the U.S. Military Academy at West Point:

"A cadet will not lie, cheat, steal, or tolerate those who do."

The words express the integrity expected of those who lead our men and women into battle, and they have a purpose: Officers who cannot be trusted have no place in positions of responsibility, not when the consequences of such a character flaw can be death, not when the American people put such confidence in those in uniform.

But somehow, it is hard to square that admirable code of honor with the Army's behavior in the Pat Tillman case. It is not merely individual officers --- from lowly captains to three-star generals --- who apparently failed to tell the truth about what happened to the former NFL star in the hills of Afghanistan. The deception is so broad that it implicates the Army as an institution.

Tillman's story is heartbreaking. After the attacks of Sept. 11, 2001, he rejected a $3.6 million contract from the NFL's Arizona Cardinals to enlist, along with his brother, as an Army Ranger. And while his decision drew widespread media attention, Tillman refused all interview requests. To him, it wasn't about the spotlight, it was about doing his duty.

But on April 22, 2004, Tillman was killed while on patrol with his unit near the Pakistan border. Immediately, the Army put out the word that he had died heroically, protecting his fellow soldiers in a firefight.

A week later, Lt. Gen. John Abizaid, the head of U.S. Central Command, told the press that a day earlier he had discussed "that firefight where Pat Tillman lost his life" with Tillman's platoon leader.

On April 30, the Army posthumously awarded Tillman the Silver Star for bravery, stating that Tillman died in a heroic charge up an enemy-held hill. "Corporal Tillman put himself in the line of devastating enemy fire. . . . While mortally wounded, his audacious leadership and courageous example under fire inspired his men to fight with great risk to their own personal safety, resulting in the enemy's withdrawal and his platoon's safe passage from the ambush kill zone."

The truth, though, was that Tillman had been killed by three bullets to the forehead fired by American soldiers in a friendly fire accident, and Army officials knew it immediately. Officers on the scene knew it, which may be why they ordered that Tillman's body armor and uniform be burned. Abizaid knew it when he made those comments to the press a week after Tillman's death. The officers who drafted the false Silver Star citation knew it, too.

The truth, or at least some version of it, finally began to emerge on May 28, 2004. It's unlikely the concession came voluntarily, given the elaborate lies the Army had spread earlier. Army officials probably realized that the jig was up, that too many people knew the facts. Tillman's brother, for example, had been nearby when Tillman died, although he, too, had been lied to about what happened.

Eventually, seven soldiers in Tillman's unit were mildly punished for their role in his death. No one has been punished for lying to the American people. But last week, the Army inspector general recommended the launching of a fourth investigation into the tragedy. The goal is to explore possible charges of gross negligence leading to Tillman's death, and to determine how the public was so misled.

Mistakes made in the heat of battle, out in the field, are a serious thing. But they are also part of war. Calculated lies by military bureaucrats, aimed at the American public, are something else entirely.

And unfortunately, the Tillman case is just one of several cases raising questions about the credibility of senior military officials.

For example, Maj. Gen. Geoffrey Miller, the former commander at the Guantanamo Bay prison camp, has repeatedly denied that he exported Guantanamo-style torture to Abu Ghraib prison in Iraq. But now that two enlisted men at that facility are being tried for prisoner abuse, Miller refuses to repeat that claim under oath, citing his right not to incriminate himself.

In a related case, Lt. Gen. Ricardo Sanchez denied to Congress that he had authorized abusive interrogation techniques at Abu Ghraib. But later, a document surfaced signed by Sanchez directly contradicting that testimony.

In both cases, deception by general officers may be leaving their subordinates unfairly exposed to prosecution. That's a far more serious breach of military honor than the Tillman affair, a breach that strikes at the foundation of military discipline.